Given the increasing use of electrical controls in vehicles, whether land vehicles or aircraft, it is now common practice to fit such vehicles with electrical units that contain electrical cards including power components. In order to facilitate the maintenance of an electrical unit, functions are generally performed by components that are grouped together in power modules, each of which comprises power components and control components.
In existing cards, power buses are generally made in the form of multi-layer circuits, each module being powered by a conductor plane that is made from a single layer. That configuration makes it possible to adapt the layout of the power supply planes to the arrangement of the power components on the card.
Nevertheless, the currents that are conveyed in power modules may reach large magnitudes, for example several tens of amps. Such currents heat the conductors, and present devices provide poor diffusion of heat, such that the temperature inside an electrical card can reach critical values, in particular when the electrical card is mounted in an airplane that is designed to fly at high altitudes where the air is rarefied, or indeed in the event of a failure of a fan device in the electrical unit that supports the electrical card.